#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h>
#include <stdlib.h>

struct ListNode {
	int val;
	struct ListNode* next;
	
};


struct ListNode* removeElements(struct ListNode* head, int val) {
    struct ListNode* newhead = NULL, * tail = NULL;
    struct ListNode* cur = head;
    while (cur)
    {
        if (cur->val != val)
        {
            if (tail == NULL)
            {
                newhead = tail = head;
            }
            else
            {
                tail->next = cur;
                tail = tail->next;
            }
            cur = cur->next;

        }
        else
        {
            struct ListNode* next = cur->next;
            free(cur);
            cur = next;
        }
    }
    if (tail)
        tail->next = NULL;

    return newhead;
}

int main()
{
	struct ListNode* n1 = (struct ListNode*)malloc(sizeof(struct ListNode));
	struct ListNode* n2 = (struct ListNode*)malloc(sizeof(struct ListNode));
	struct ListNode* n3 = (struct ListNode*)malloc(sizeof(struct ListNode));
	struct ListNode* n4 = (struct ListNode*)malloc(sizeof(struct ListNode));
	n1->val = 1;
	n2->val = 2;
	n3->val = 3;
	n4->val = 4;

	n1->next = n2;
	n2->next = n3;
	n3->next = n4;
	n4->next = NULL;

	removeElements(n1, 2);

	return 0;
}

